Congratulations Kiran
you may need to upload
1. Birth Certificate (english translated if the same is in native language)
2. Passport of child
and please use I-864W ( if the Child has USC Biological Parent)
Please check the link below for scans
https://travel.state.gov/content/travel/en/us-visas/immigrate/the-immigrant-visa-process/step-8-scan-collected-documents.html